1. Field of the Invention
This is a continuation in part of application Ser. No. 309,939 filed Oct. 9, 1981, now abandoned.
The present invention relates to a method of and apparatus for measuring an unbalance value of a wheel mounted on a body of an automobile.
2. Description of the Prior Art
A method and apparatus have hitherto been proposed for measuring an unbalance value of a wheel in which a pickup for detecting a vertical vibration of the wheel is mounted in the vicinity of the wheel which has been lifted by means of a jack. The wheel is rotated by a wheel driving device frictionally engaged therewith and an output voltage signal is obtained from the pickup. On the one hand, a position where a counter-weight for balancing the unbalance is to be mounted is determined by flashing a lamp according to said output voltage signal as in the known strobo method in which, when the most weighty portion of the wheel while it is rotated reaches a lower dead point or a lowermost position, the lamp is flashed so that the most weighty portion of the wheel can be observed as if in a stationary state. On the other hand, the value of the counter-weight for balancing to be attached on the wheel is determined by the magnitude of the output voltage signal of the pickup.
In such conventional method and apparatus, it is necessary to repeat the measurement in order to obtain the true value and position of the unbalance because they are affected by the kinds of wheel and automobile on which the wheel is mounted as well as the position where the pickup is mounted. Specifically, it is necessary to repeat the addition and reduction of the counterweight for balancing, thereby causing consumption of time and labor.